• 제목/요약/키워드: viscosity measurement

검색결과 336건 처리시간 0.022초

정량적 측정 시스템을 이용한 족삼리와 6가지 모델의 침감 비교 연구 (Comparative Study of Needle Sensations in $ST_{36}$ and 6 Models with Quantifying Measurement System)

  • 한예지;조수정;손영남;이수윤;김갑성;이승덕
    • Journal of Acupuncture Research
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    • 제30권5호
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    • pp.87-94
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    • 2013
  • Objectives : In this study, we intended to make the foundation of the development of acupuncture tissue model as comparing the needle sensation of six kinds of tissue models and Zusanli ($ST_{36}$) with the needle force measurement system. Methods : When practitioners did twisting-rotating acupuncture needle manipulation after inserting the needle into six kinds of tissue models, they quantified the similarity sense to the sensation of Zusanli ($ST_{36}$) with the NRS (Numeric Rating scale). As needle force measurement system did twisting-rotating Acupuncture needle manipulation after inserting needle into Zusanli ($ST_{36}$) of human and six kinds of tissue models, it can calculate the coefficient of viscosity by measuring the torsion friction. We compare the NRS of practitioners' needle sensation to the coefficient of viscosity of needle force measurement systems. Result : As practitioners' NRS assessment to quantify needle sensation, apple and cucumber showed 70% similarity to Zusanli ($ST_{36}$). As needle force measurement system's coefficient of viscosity, apple and cucumber's coefficient of viscosity were similar to Zusanli ($ST_{36}$)'s. Conclusions : In this study, We compared the practitioners' needle sensation of Zusanli ($ST_{36}$) and six kinds of tissue models with needle force measurement system that can quantify the needle sensation. As the result, we concluded that practitioners' needle sensation is similar to measured needle sensation. It seems that the acupuncture practice model implementing the needle sensation to specific acupuncture points can be built based on the system in this study.

RHEOLOGICAL PROPERTIES OF MAGNETIC PARTICLE SUSPENSIONS

  • Kwon, T.M.;Choi, H.J.;Jhon, M.S.
    • 한국자기학회지
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    • 제5권5호
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    • pp.667-671
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    • 1995
  • The viscometric technique is used to study the effects of microstructure on the viscosity (viscosity vs. concentration or shear rate) of magnetic particle suspensions. In this characterization, measurement of suspension viscosity is used to obtain the dependence of viscous energy dissipation on microstructural state of dispersions. Microstructural shape effects which are related to particle orientation are then indirectly obtained. Empirical formulas from mean field theory and the Mooney equation, which are applicable at high concentration of magnetic particles, are used to relate viscosity to particle concentration. The validity and physical meaning of these equations are discussed.

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점도측정법을 이용한 방사선 조사 건조농산품의 검지 가능성 (Potential Detection of Irradiated Dried Agricultural Products by Viscosity Measurement)

  • 권중호;정형욱;정재영
    • 한국식품영양과학회지
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    • 제28권5호
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    • pp.1082-1086
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    • 1999
  • Dried vegetables, white ginseng and spices, which were exposed to gamma and electron beam irradiation, were used in a detection study by measuring their starch content and viscosity change. The samples tested showed different levels of starch content(15.64~60.86%), which was not directly proportional to the viscosity of the samples. The correlation coefficients between irradiation dose and viscosity change were lower in the samples, such as cabbage, carrot, clean vegetable(chunggyungchae), garlic, mushroom, green onion, and red pepper, while some higher coefficients were found in ginger(R2=0.9271), white ginseng (R2=0.6223) and onion (R2=0.7909). Thus, dried ginger and white ginseng were selected to be used for a detection of irradiated samples using specific parameters(threshold values). Specific parameter for the nonirradiated ginger and ginseng were 13.31 and 13.93, respectively. On the other hand, gamma and electron beam irradiated samples at 2.5 kGy, the lowest dose for a commercial purpose, showed decreased values, 11.92 and 11.15 in ginger, and moreover 4.40 and 5.10 in ginseng. It is expected that a proportional decrease in a specific parameter with the absorbed doses will be a potentially useful index for detecting whether starchy foods have been irradiated or not.

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Relationship between Apparent Viscosity and Line-Spread Test Measurement of Thickened Fruit Juices Prepared with a Xanthan Gum-based Thickener

  • Kim, Sung-Gun;Yoo, Whachun;Yoo, Byoungseung
    • Preventive Nutrition and Food Science
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    • 제19권3호
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    • pp.242-245
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    • 2014
  • The flow behaviors of three thickened fruit juices (orange, apple, and grape juice) prepared with a commercial instant xanthan gum (XG)-based thickener that is marketed in Korea were investigated at different thickener concentrations (1.0%, 1.5%, 2.0%, 2.5%, 3.0%, and 3.5%) and setting times (5 and 30 min) using a rheometer and a line-spread measurement method. The flow distance values measured by the line-spread test (LST) were compared with the apparent viscosity (${\eta}_{a,50}$) values measured with a sophisticated computer-controlled rheometer. The ${\eta}_{a,50}$ values of the juices increased as thickener concentration increased, whereas their flow distances decreased. The ${\eta}_{a,50}$ values at the 30-min setting time were much higher than those at the 5-min setting time, indicating that the setting time before serving or consuming thickened juices can affect viscosity values. Plots comparing ${\eta}_{a,50}$ values to LST flow distances revealed strong exponential relationships between the two measures ($R^2$=0.989 and $R^2$=0.987 for the 5- and 30-min setting times, respectively). These results indicate that the LST can be a suitable instrument for evaluating the viscosity of thickened fruit juices prepared with different XG-based thickener concentrations and setting times for the dysphagia diet.

연속섬유강화 플라스틱 복합재의 압축성형에 있어서 확대/축소 점도비를 고려한 유동해석 (Flow Analysis with Ratio of Expansional /Contractional Viscosity during Compression Molding of Continuous Fiber-Reinforced Polymeric Composites)

  • 김형철;채경철;조선형;김이곤
    • 대한기계학회논문집A
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    • 제24권3호
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    • pp.581-592
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    • 2000
  • To obtain an excellent product and decide on optimum molding conditions, it is important to establish the relationship between molding conditions and viscosity. The composites is treated as a pseudoplastic fluid, and the expansional/contractional viscosity of the fiber-reinforced polymeric composites is measured using the parallel plastometer, and the model for flow state has been simulated with the viscosity. The effects of expansional slip parameter $\alpha_{e}$, and expansional/contractional viscosity ratio ${\mu}_{\gamma}$, on the mold filling parameters are also discussed.

고분자 전해질막 수소 연료 전지 분리판 용 고분자/흑연 복합 재료의 혼합 및 유변학적 특성에 관한 연구 (Study on Mixing Characteristic and Rheology of Polymer/Graphite Composites for a Bipolar Plate of Polymer Electrolyte Membrane Fuel Cell)

  • 유태현;김동학;손영곤
    • 한국산학기술학회논문지
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    • 제12권10호
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    • pp.4673-4678
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    • 2011
  • 이 연구에서는 고분자 전해질 막 연료전지의 분리판 용 고분자/흑연 복합소재의 혼합 특성 및 점도 측정 방법에 관하여 연구하였다. 분리판은 전도성이 있어야 하기 때문에 흑연의 함량이 매우 높고 이 때문에 제조된 복합재료의 점도가 높아 점도 측정이 어려운 문제가 있다. 일반적으로 캐필러리 레오메터에서 사용되는 다이로 점도를 측정한 결과 압력이 시간에 따라서 계속 변하고 정상상태의 값을 보이지 않아서 점도 측정이 불가능 했다. 다이의 디자인을 변경하여 측정하면 압력이 정상상태를 보이는 것을 관찰할 수 있었으나, 흑연과 PET를 단순 용융 혼합하여 점도를 측정하는 경우에는 측정된 점도 값이 재현성이 없는 결과를 나타냈다. 여러 차례의 시행 오차 끝에 흑연과 PET를 작은 입자로 분쇄한 후 용융 혼합하면 재현성 있는 점도를 측정할 수 있고, 제조된 복합재료의 전기전도도 값도 재현성 있는 결과를 보임을 관찰하였다.

Measurement of red cell deformability and whole blood viscosity using laser-diffraction slit rheometer

  • Sehyun Shin;Yunhee Ku;Park, Myung-Su;Suh, Jang-Soo
    • Korea-Australia Rheology Journal
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    • 제16권2호
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    • pp.85-90
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    • 2004
  • The present study investigated the deformability of red blood cells (RBC) and its effect on whole blood viscosity using a laser-diffraction slit-rheometer (LDSR). The LDSR has been recently developed with significant advances in laser-diffractometry design, operation and data analysis. While shear stress levels in a slit flow are continuously decreasing, both the deformation of red blood cells and the shear stress were simultaneously measured. Additionally, the viscosity of whole blood was measured using the LDSR. The present study found that the whole blood viscosity is strongly dependent on the RBC deformability. The less deformable the RBCs are, the higher the blood viscosity is.

섬유강화 플라스틱 복합재의 성형공정에 관한 연구(일방향 섬유강화 복합재의 점도측정 및 유동해석) (A Study on Molding Process Fiber Reinforced Plastic Composites (Flow analysis Measurement of viscosity of Unidirectional Fiber Reinforced Plastic Composites))

  • 조선형;안종윤;이국웅;윤성운
    • 한국공작기계학회논문집
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    • 제10권2호
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    • pp.103-114
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    • 2001
  • During a compression molding process of Unidirectional Fiber Reinforced Plastic Composites, control of filling patterns in mold and distribution of fiber is needed to predict the effects of molding parameters on the flow characteristics. To obtain an excellent product and decide optimum molding conditions, it is important to know the relationship between molding conditions and viscosity. In this study, the anisotropic viscosity of the Unidirectional Fiber Reinforced Plastic Composites is measured by using the parallel plastometer. The model for flow state has been simulated by using the viscosity. The composites is treated as an incompressible New-tonian fluid. The effects of longitudinal/transverse viscosity ration A and slip parameter $\alpha$ on buldging phenomenon and mold filling patterns, are also discussed.

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